Hii, sorry for the very late reply, I was a bit busy and I didnt notice your addon discussion on the potato edition, Anyway, the programs I use are the following:
1. Photoshop cs6 with Nvidia DDS plugin (to manually convert specific dds without destroying their normal and specular maps)
2. Ordenador (A Fallout DDS tool that can batch convert DDS files but be wary, this does not convert the normals and specular maps properly.)
3. DDSopt (A bit more complicated app but it's best compared to Ordenador when optimizing dds)

That's all! Goodluck!